Abstract: The invention relates to a method for extracting ground attribute data in interferometry synthetic aperture radar data, and aims at providing a method for extracting ground attribute data in PS data. The method comprises the following steps that ground geographic data are led; ground boundary data are contracted inwards by Tx in the east-west direction, and are contracted inwards by Ty in the south-north direction, and a new ground boundary is determined again; whether each PS point falls into the new ground boundary or not is judged, and if yes, the data are extracted; if not, the data are removed; a first data set after extraction is obtained; whether the gray value of a PS point image in the first data set is between Vmin and Vmax or not is judged, and if yes, the data are further extracted; if not, the data are removed. The ground attribute data are extracted through the method, so that the accuracy of PS points is 95.1 percent.

Abstract: A riser reactor for propylene production, comprises pipelines with an upper part and a lower part, the upper part is a straight pipeline, and the lower part is a expanding-diameter pipeline, and the expanding-diameter pipeline is a circular truncated cone-shaped pipeline with an angle of 1˜60 o between generatrix and axes, wherein, the diameter of upper surface of the circular truncated cone-shaped pipeline is larger than or equal to the diameter of the straight pipeline. Employed the riser reactor, propylene is produced by the method of catalytic cracking with stratified injections of heavy oil and light olefins. Average gas linear velocity in axial direction of the straight pipeline of riser reactor is 3˜25 m/s, and that in the expanding-diameter pipeline is 0.1 to 5 m/s. The outlet temperature of the riser reactor is 460 to 600° C., and the light olefins are no more than 50% of the total feedstock by weight.